Theodore Rockwell, 90, a nuclear engineer who assisted in the development of nuclear-powered naval vessels and the establishment of a Washington-based company specializing in nuclear engineering, died of mesothelioma March 31 at home in Chevy Chase.

A son, Teed Rockwell, confirmed the death.

At his death, Mr. Rockwell was chairman of the board of the engineering company MPR Associates, which he established with two colleagues in 1964. He retired officially at the age of 65 but had continued working on a reduced schedule.

Since 1943, he had been involved in the application and development of nuclear power. During World War II, he worked on the atomic bomb project at Oak Ridge, Tenn. After the war, he worked with Navy Adm. Hyman G. Rickover on the development of the Navy’s nuclear propulsion program.

Mr. Rockwell settled in the Washington area in 1949.

He received distinguished service medals from the Navy and the Atomic Energy Commission. He also received the American Nuclear Society’s Lifetime Achievement Award, which is now known as the Rockwell Lifetime Achievement Award.

Theodore Rockwell was born in Chicago. He graduated from Princeton University in 1943 and received a master’s degree in chemical engineering from Princeton in 1946.

Mr. Rockwell was the author or co-author of books on the history of nuclear technology and also wrote a novel.

His wife of 63 years, Mary Compton Rockwell, died in 2009. A son, Robert Rockwell, died in 1997.

Survivors include three children, W. Teed Rockwell of Berkeley, Calif., Larry Rockwell of White Post, Va., and Juanita C. Rockwell of Baltimore; and two grandchildren.

— Bart Barnes